I understand that, unless its recessive gene, as that is the only rooster they had on the property and the chicks were brooded with moms enclosed and both laid a light olive colored egg not. I have an Americauna rooster on Rhode Island Red hens and get the blue green shells, but she wasn't hatched outta my flock and do know the people that hatched her outThat doesn't produce olive eggers. Not even close.
You need a blue egg gene in one parent for that.